Centrifugal drier



NOV. 7, 1939 I c GARLAND 2,178,750

CENTRIFUGAL DRIER Filed March 17, 1938 Patented Nov. 7, 1939 UNITED STATES PATENT OFFICE 4 Claims.

My invention relates to apparatus for removing moisture from granular material such as coal, sand, gravel and the like, in which the moisture is removed by rotating the mass of material at high speed so that any surface moisture is thrown out by centrifugal force. My improvement in this type of equipment consists in admitting hot gases to this equipment and causing the hot gases to pass through the material as it rotates and passes through the drier. These gases, in passing through the material, entrain a certain amount of moisture and carry this out in mechanical suspension thereby assisting the centrifugal action, and in addition to this, the heat in the gases evaporates a portion of the moisture in the material. The object of my invention is therefore to improve the drying performance of centrifugal drying equipment by passing hot gases through the material in its passage through the drier.

Referring to the drawing, in which like numerals refer to like parts, Figure I is a section through my improved centrifugal drier. This driercomprises a shell 1, closed at the top by a cover plate II. On the cover plate H is mounted an outlet for hot gases l2, and an inlet 52 for the admission of the material to be dried. To the inlet 52 communicates a pipe 3| to which is attached a screw conveyor 6. This screw conveyor comprises the screw 9, mounted on the shaft 29, which is in turn mounted in the bearings 8 and 43. To the end of the shaft 29 is rigidly attached a sprocket H), which may be driven by a chain from any convenient source of power. On the casting 52 is provided a bearing M in which is mounted a shaft 2|. The lower end of the shaft 2! is mount ed in a bearing 5, which is supported by arms #3, mounted in the shell 2, which is in turn bolted to the shell i at 5. On the shaft 2| and rigidly attached thereto by means of the keys 2!), hubs it and 22, and the arms 25 and i3, is mounted a cone 26, which is adapted to rotate with the shaft. This cone 26 is made up of horizontal ribsifi, and vertical ribs 53. The open spaces M are covered over by perforated plates or screens l1. On the shaft 2| is also rigidly mounted a distributor plate 23 on which are located ribs 43, usually four in number. In the shell 2 is located a drip pipe 23 for discharging any water that may accumulate. To the shell 2 is bolted at 46 the shell 3, which is provided with a conical bottom 41. In the shell 3 is mounted the truncated cone 31, and the diaphragm 36, which form, with the sides of the shell 3, an annular space of triangular section. To the annular space communicates the elbow 35,

the pipe 34, which in turn communicates with the pipe 21. The pipe 21 extends through the conical bottom 41 of the shell 3, and has an exit 30 adapted to discharge gases to the cone 33, provided with perforations 39 in the side wall. The perforations 33 are about one-eighth of an inch wide and about four inches long. In the bottom of the cone &1 is located the paddle wheel M, mounted on the shaft 33, which is in turn supported in the side walls of the material discharge outlet 42, which is of rectangular section. On the shaft 3| is mounted a pulley 30, which is adapted to be driven by any'convenient source of power:

The pipe 21 is attached to the bottom code 61 at 50, and forms a support for the cone 33.

The operation of my device is as follows:

The material to be dried is discharged to the magazine or hopper 1, and the screw Q is rotated by means of a sprocket attached to the shaft 29, which is driven by a chain from any convenient source of power. As the screw 9 rotates, the material to be dried passes down through the pipe 3|, between the arms '25, and onto the spreader 23. Theshaft 2 i, the cone 26, and the spreader 26, are rotated by means of a belt applied to the wheel 28. As the cone 26, and the spreader 24$, rotate; the centrifugal force throws the material from the spreader 23 onto the inner surface of the cone 23, which consists sf screens l1. Due to centrifugal action the-material passing oil the spreader 24! onto the cone 2%, gradually descends along the surface of the cone and the water contained in the material, due to the centrifugal force, passes out through the perforations in the screens i1. As the material leaves the screens i1, and the rotating cone 28, the material drops onto the inverted truncated cone 31, descends the side walls of this truncated cone by gravity, and is discharged onto the done 33, and from the cone 33 discharges into the inverted cone d1, forming the bottom of the shell 3.

As the material is descending through the drier; hot gases enter through the pipe 21, pass upward through the pipe 3%, and enter at 35 the annular compartment 33.. At the same time another por tion of the gases entering through the pipe 21 passes up through the pipe 3% and out, through the perforations 33 in the cone 33. At the same time the gases entering the compartment 63, pass through the perforations 38 in the inverted truncated cone 31 and the material passing thereover. The gases passing upward from the cone 33 and the truncated cone 31 enter the bottom of the cone 26, pass through the material dement and at the same time reduce the moisture pass out through the opening I2.

by evaporation. Any dust picked up by the gases in the lower part of the drier is scrubbed out by the wet material passing over the screens II, as the gases pass out.

While I have shown only one inverted truncated cone 31, and one cone 33, which form a pair, as many of these pairs of units may be installed as is necessary to obtain the proper degree of dryness. This may result in the use of one pair, or possibly flve or six pairs.

During the operation of the equipment the material passing through the screw conveyor 6 forms a seal to prevent the escape of hot gases which Likewise, the paddle wheel 4|, rotating by means of a belt on the wheel 40, retards the discharge of material from the cone 41, thereby sealing oil. the cone 4! and preventing the escape of gases at this point. The fuel charging device at the top consisting of a screw conveyor 6, may also be used as a discharging device at the, bottom of the drier. At 23 is provided a drip connection for any accumulated water, which consists of a pipe communicating with the shell I, and sealed in water to prevent the escape of hot gases by means of the seal I.

It will be seen from the above description that I have provided means for greatly increasing the emciency of centrifugal drying equipment. While the parts shown and described are the preferred arrangement of my equipment, it should be understood that my invention is not limited to the precise construction set forth, but contains within its purview such changes as may be made within the scope of the appended claims.

What-I claim and desire to secure by Letters Patent is: I

1. In a centrifugal drier of the type described, a shell, a material charging device mounted near the top of the said shell and adapted to supply material thereto, a material discharging device located near the bottom' of the said shell and adapted to discharge material therefrom, a shaft vertically mounted within the said shell and adapted to rotate therein, a distributing device 24 mounted on the said shaft adapted to receive material discharged from the said material discharging device, a truncated conical member supported from the said shaft and adapted to receive on its inner sides material from the said distributing device, means for rotating the said shaft, the said distributing device and the said truncated conical member whereby materials charged to the shell by means of the said material charging device is distributed from the said distributing member onto the inner surface of the said truncated conical member, an inverted truncated perforate cone beneath the said truncated conical device, means for discharging gases through the perforations in the said inverted truncated cone, and a gas outlet near the top of the said shell.

2. In a centrifugal drier of the type described, the combination of a shell, a material charging device mounted near the top of the said shell and adapted to supply material thereto, a material discharging device located near the bottom of the said shell and adapted to discharge material therefrom, a shaft vertically mounted within the ical member supported from the said shaft and adapted to receive on its inner sides material from the said distributing device and the said truncated conical member mounted thereon whereby material charged to the shell by means of the said material charging device is distributed from the said distributing member onto the inner surface of the said truncated conical member, an inverted truncated perforate cone beneath the said truncated conical device, means for discharging gases through the perforations in the said inverted trunc ted cone, a perforate cone beneath the said inverted truncated perforate cone, means for discharging gasesthrough the perforations in the said perforate cone, and a gas outlet near the top of the said shell.

. 3. In a centrifugal drier of the type described, a shell, a material charging device mounted near the top of the said shell and adapted to supply material thereto, a material discharging device located near the bottom of the said, shell and adapted to discharge material therefrom, a shaft vertically mounted within the said shell and adapted to rotate therein, a distributing device 24 mounted on the said shaft adapted to receive material discharged from the said material discharging device, a truncated conical member supported from the said shaft and adapted to receive on its inner sides material from the said distributing device, means for rotating the said shaft, the said distributing device and the said truncated conical member whereby material charged .to the shell by means of the material charging device is distributed from the said distributing member onto the inner surface of the said truncated conical member, an inverted truncated perforate cone beneath the said truncated conical device, means for discharging gases through the perforations in the said inverted truncated cone, a perforate cone mounted beneath the said inverted truncated cone, means for discharging gases through the perforations in the said perforate cone, a gas outlet near the top of the said shell, and an offset for the accumulation of water in the said shell.

4. In centrifugal apparatus of the type described, the combination of a shell, a gas outlet on the top of the said shell, a material charging device having communication with the top of the said shell, a material discharging device communicating with the bottom of the said shell, a shaft vertically mounted in the axis of the said 'shell, a

hollow truncated conical member attached to the said shaft and adapted to rotate therewith, perforations in the side of the said conical member, a distributing plate beneath the top of the said conical member mounted on the said shaft and adapted to receive material from the said material charging device and distributing same to the inner surface of ,the said conical member, a perforated inverted truncated cone beneath the said conical member, a perforated cone beneath the said truncated cone, a gas pipe for supplying hot gases to the underside of the said perforated cone, a branch gas line adapted to deliver hot gases beneath the said inverted truncated cone, an offset in the said shell, and a sealed drain connection communicating with the said offset, substantially as described.

CLAUDE M. GARLAND. 

